Mole crickets can become serious pests of turfgrasses, pastures, and vegetable seedlings. The first step in determining if you have a mole cricket problem at a site is to compare the existing damage to pictures of known mole cricket damage. If the damage is likely caused by mole crickets, specimens should be obtained and the pest identified. You then should determine if the number of mole crickets is great enough to cause an unacceptable level of damage and decide what control measures should be used. Eventually, a long-term, sustainable integrated pest management (IPM) program should be established. This guide will help you identify mole cricket infestations and manage them effectively and economically while minimizing environmental impacts.

Section 1: Observe Damage

Plants Affected

Mole crickets are most often thought of as pests of grasses, such as bahiagrass, bermudagrass, centipedegrass, seashore paspalum, St. Augustinegrass, and zoysiagrass. However, other plants that can be damaged by mole crickets include but are not limited to beet, cabbage, cantaloupe, carrot, cauliflower, chrysanthemum, chufa, coleus, collard, eggplant, gypsophila, kale, lettuce, onion, peanut, pepper, potato, rice, spinach, strawberry, sugarcane, sweet potato, tobacco, tomato, and turnip.

Damage Caused

Mole cricket feeding and tunneling can damage or kill the affected plants, especially during warm and moist summer months when the nymphs are rapidly developing. Feeding on the underground plant parts can cause an overall decline, dead patches, and little to no root mass. In pastures, mole-cricket-infested grass may be uprooted by feeding livestock, rendering the grass unavailable for additional grazing. When mole crickets tunnel in the upper ten inches of the soil surface, plants can become dislodged or have limited water uptake. Moreover, tunneling can create raised surface ridges that disrupt ball roll on golf courses (Figure 2). It may be a symptom of mole cricket activity when plants appear drought-stricken even after sufficient irrigation (Figures 3). Vegetables and other plants are also affected through underground feeding on roots or tubers, and above-ground feeding on foliage or stems, along with their tunneling activity. Above-ground feeding often results in girdling around the base of the stem, or at times the entire plant may be chewed off and taken into a tunnel as food and consumed. This girdling is especially common in seedlings. Flying adult mole crickets are attracted to lights at night, and they often burrow into moist soil nearby to mate and lay eggs. An initial adult mole cricket infestation thus may be localized around outdoor light sources and/or sprinkler heads. After egg hatch and as the next-generation nymphs mature and disperse, greater areas become damaged.

Figure 2.

Characteristic mole cricket tunnels.

Credit:

N. Leppla, UF/IFAS

[Click thumbnail to enlarge.]

Figure 3.

Dead patches caused by mole crickets feeding on turfgrass.

Credit:

E. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Section 2: Collect Samples

Sampling is a critical part of a well-designed IPM program; it is important to know which pests are present and roughly how many there are. Doing a soap drench can bring mole cricket nymphs and adults to the soil surface, so their species and relative age can be determined. How many insects emerge from the soil may provide an idea of how bad an infestation is, but tunneling severity within a defined area may be more useful for decision-making. Below is a simple drench test for collecting specimens to be identified and for estimating mole cricket population densities. In this procedure, several 4 ft2 samples are taken from soil that must be moist:

Mark out a 2 ft. x 2 ft. area where mole cricket activity is suspected.

Evenly pour the soap solution over the marked area.

Observe the area for 3 minutes; count and collect the mole crickets that emerge.

In many cases, control actions are justified if two or more mole crickets surface during the 3-minute sampling period. See Section 4, “Establishing Damage Threshold,” for more information to help you determine whether to treat.

Section 3: Identify Pest

Three non-native pest species of mole crickets occur in Florida: the shortwinged mole cricket, Scapteriscus abbreviatus Scudder; the southern mole cricket, Scapteriscus borellii Giglio-Tos; and the tawny mole cricket, Scapteriscus vicinus Scudder. All three are believed to have been unintentionally transported into the southeastern United States around 1900. It is necessary to distinguish the native, non-pest species of mole cricket, genus Neocurtilla, from the invasive mole crickets in the genus Scapteriscus. Native mole crickets have four dactyls (claws) on the forelegs and the pest mole crickets have two (Figure 4).

Figure 4.

Differences in dactyls between native and invasive mole crickets.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Figure 5.

Identification of invasive mole cricket species.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Mole Cricket Life Cycle

Eggs (Figure 6): The female builds a circular egg chamber in the soil near one of the tunnels. The 3- to 4-cm-diameter chambers are placed 5-30 cm below the soil surface. Eggs are deposited in a cluster within the egg chamber, each mass containing 25-60 eggs. Eggs are gray to brownish and roughly oval, measuring about 3 mm long and 1.7 mm wide when fresh. Through the absorption of water, the eggs reach a final size of about 3.9 mm long and 2.8 mm wide. Egg development requires 10-40 days, depending on the soil temperature. A female produces 2-5 egg masses in a lifetime.

Figure 6.

Shortwinged mole cricket eggs close to hatching.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Nymphs (Figure 7): Recently hatched nymphs, called first instars, are whitish but darken to their mature color during the first 24 hours. First instars may consume the egg shell or cannibalize siblings; however, they soon leave the egg chamber and burrow to the soil surface. Nymphs and adults are similar in appearance, except nymphs have underdeveloped external wings called wing-pads. Development time of nymphs varies, requiring 23-38 weeks during which they go through 8-10 instars before becoming adults.

Figure 7.

Shortwinged mole cricket nymphs (note the lack of wings).

Credit:

J. Castner, UF/IFAS

[Click thumbnail to enlarge.]

Adults (Figure 8): Adult mole crickets are light yellowish to dark brownish and measure 22-33 mm in length, depending on the species. They have enlarged forelegs with dactyls, blade-like projections used for digging. Their antennae are shorter than the body, and they have two long sensory appendages called “cerci” at the tip of the abdomen. Tawny and southern mole crickets become active at dusk when each male emits a “song” from its burrow that attracts a female of the same species. They mate within the burrow, after which the female may eject the male and occupy the burrow. Unlike the other two species, the shortwinged mole cricket male produces only a weak pulsing chirp that attracts a female.

Figure 8.

Tawny mole cricket adult.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Mole Cricket Seasonal and Geographic Distribution

The shortwinged mole cricket

The shortwinged mole cricket occurs mainly in coastal regions, with sandy soils (Figure 9). Since it is flightless, the species has not spread as extensively as the other two pest mole crickets. It currently has a limited geographical range in Florida, but all life-stages can occur year-round.

Figure 9.

Distribution of the shortwinged mole cricket.

Credit:

T. Walker, UF

[Click thumbnail to enlarge.]

The southern mole cricket

The southern mole cricket occurs across much of the southeastern United States from southern North Carolina to central Texas (Figure 10). It also has been reported recently in Yuma, Arizona, and Los Angeles County, California. It is distributed throughout Florida, occurring primarily in moist, sandy areas. This mole cricket usually has one generation per year, but it has two in southern Florida. Peak flights generally occur from April to June, with an additional minor flight around November. However, in south Florida, a second major flight usually occurs in July.

Figure 10.

Distribution of the southern mole cricket.

Credit:

T. Walker, UF

[Click thumbnail to enlarge.]

The tawny mole cricket

The tawny mole cricket occurs within several miles of the Atlantic and Gulf coasts from North Carolina to eastern Texas (Figure 11). However, it is distributed throughout Florida and primarily inhabits well-drained, moist, sandy areas. This mole cricket has one full generation per year with peak flights generally occurring in March-May, with an additional minor flight in the fall. After December, nearly all mole crickets in flight are the tawny mole cricket. Egg hatch occurs in April-June, after which nymphs develop for five months and become adults as early as September.

Figure 11.

Distribution of the tawny mole cricket.

Credit:

T. Walker, UF

[Click thumbnail to enlarge.]

Section 4: Establish Damage Threshold

The amount of plant damage a homeowner or site manager determines is tolerable is called the “damage threshold.” It varies with the site and expectations for plant quality. On athletic fields and golf courses, the more intensive management practices, lower cutting heights, and esthetic standards may dictate lower thresholds. In vegetable production, on the other hand, acceptable levels of damage may be low during the seedling stage but higher as the plants mature. Thresholds are highly subjective and vary with the condition of the plants.

The damage mole crickets cause is related to the species, stage, and number of mole crickets that infest the site. Tawny mole crickets, for instance, cause a relatively high degree of destruction, and a range of 2-4 adult mole crickets per 4 ft2 is a general upper limit warranting management action for turf, though most managers set the damage threshold somewhat higher for pastures. The plant damage nymphs cause increases as they grow and disperse. Continue sampling and re-evaluating thresholds throughout the mole crickets’ life cycle to watch for increases both in the number of mole crickets and the damage they are causing. Ultimately, the severity of a mole cricket infestation and the associated damage threshold will dictate which control options will be most effective and economical.

Section 5: Select Management Options

Options for managing mole crickets in turfgrass include cultural control, biological control, and chemical control. Properly integrating several options will provide the greatest level of long-term control. After verifying the species, stage, and relative abundance of mole crickets, and deciding on a reasonable action threshold, select management practices from the following options:

Cultural Control

Cultural controls are steps taken in the management of a site that can make it less attractive or supportive for mole crickets. Steps may include selecting tolerant plant cultivars, altering soil moisture, reducing attractive lighting, and changing various growing practices. Cultural controls, such as lighting, may be implemented individually or used in conjunction with other methods.

Tolerant Cultivars

No turfgrass species or cultivar is completely resistant to mole cricket damage, although centipedegrass, St. Augustinegrass, and zoysiagrass are considered the least frequently injured. Bahiagrass, bermudagrass, and seashore paspalum tend to be the most susceptible to damage caused by mole crickets. Table 1 describes some susceptible and tolerant turfgrass cultivars.

Soil Moisture

Soil moisture can affect mole crickets, significantly increasing plant damage at irrigated sites. Mole crickets remain closer to the soil surface when the soil is moist but tunnel deeper when the soil is dry. Rain after a long dry period causes an increase in the number of mole crickets in flight and may increase the number attracted to lights. During periods of egg-laying, females prefer to lay more eggs in irrigated areas than in non-irrigated ones. Egg survival decreases under drought conditions. Long-term control of soil moisture generally is not an option because it would disrupt plant growth, but the response of mole crickets to soil moisture can be used to time pest management practices. For example, insecticides could be more effective if applied after irrigation that brings mole crickets closer to the soil surface. Alternatively, flooding can drown the mole crickets or force them to move to higher ground where insecticides can be applied as spot treatments.

Lighting

Mole crickets fly at dusk for 1-2 hours during which they are attracted to light, especially ultraviolet and mercury-vapor lamps. To limit the incidence of mole crickets in turfgrass, lights should be turned off at a site during times of peak flight. Conversely, lights can be used to attract mole crickets for spot treatment with insecticides. If lights are necessary, yellow bulbs or filters can be used to minimize attraction of mole crickets.

Tillage

The objective of tilling is to expose mole crickets to predation or desiccation and kill them mechanically. Feeding by birds may be promoted by tilling, for example. In addition to exposing or damaging the insects, tilling can destroy their burrows and cause them to relocate. Tilling generally is not used on turfgrasses but can be effective on agricultural sites. Till when eggs and young nymphs are present because these life stages are more palatable to birds and less able to resist desiccation, so they are more likely to be killed than adults.

Plant Health

The plant’s health can affect its tolerance to damage by mole crickets. Maintaining proper fertilization, irrigation, and soil conditions is important. For turfgrasses, leaving sufficient shoot growth after mowing is important because cutting too close increases stress on the grass. Mowing height recommendations are given in table 2. For pastures, overgrazing should be avoided as this can cause significant stress to the grass.

Record Keeping

Areas that historically have been infested by mole crickets are likely to be re-infested. It therefore is important to document and map these preferred mole cricket habitats. Monitor these areas intensively so that you can implement control measures quickly before damage thresholds are exceeded.

Biological Control

Biological control is the use of living natural enemies to control pests. Natural enemies can be predators, parasites, pathogens, or competitors. Populations of some natural enemies may be augmented by habitat manipulation. In some cases, natural enemies can be produced in large quantities and released at sites that have too few established natural enemies to effectively limit pest populations, keeping it below the damage threshold. For pest mole crickets in Florida, widespread applications have been made of the entomopathogenic mole cricket nematode, Steinernema scapterisci, in addition to releases of the Larra wasp, Larra bicolor, and Brazilian red-eyed fly, Ormia depleta. These non-native natural enemies were imported, tested for safety and released by the UF/IFAS Mole Cricket Research Program. All are currently present in Florida, but none are available commercially. Specifics on the importation and introduction of these three introduced natural enemies are given by Frank and Walker (2006).

Mole Cricket Nematode

This nematode (Figure 12) was introduced from South America and widely applied across Florida as a biopesticide until 2012. It infects large nymphs and adults, reproducing inside them to yield additional generations of nematodes. These parasites are not normally observed outside the host; they are spread throughout an area by the infected mole crickets.

Figure 12.

Steinernema scapterisci nematodes emerging from an adult mole cricket in the laboratory.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Larra Wasp

This wasp (Figures 13 and 14) was introduced from South America into south Florida in 1981, and again into north Florida in 1988, to control pest mole crickets. It parasitizes only Scapteriscus spp. and does not sting people, so it was safe to release. The adult wasp is black with a red abdomen, and its wings are clear to smoky blue. A female usually lays one egg on each mole cricket it finds. The egg hatches in 6-7 days, the larva feeds on the mole cricket for 10-11 days and kills it, then pupates in a cocoon in the soil. A new adult emerges roughly 6 weeks later during the warmer months, but those that pupate in the fall may become adults by the following April. Larra wasps lay eggs only on mole cricket adults and medium to large nymphs.

Figure 13.

Larra wasp laying an egg onto a tawny mole cricket adult.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Figure 14.

Larra wasp larva feeding on a tawny mole cricket adult.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Larra wasps require a nectar source for their survival. The shrubby false button weed, Spermacoce verticillata (a.k.a. larraflower), is the preferred nectar source (Figure 15). White flowered pentas, Pentas lanceolata, and partridge pea, Chamaechrista fasciculata, are good alternative nectar sources. If either of these plants or other nectar sources are available, larra wasps will appear and forage at least 200 yards from them to locate mole crickets. Larraflower can be invasive, so it should be contained. Partridge pea may be toxic if consumed by livestock.

Figure 15.

Larra wasp feeding on S. verticillata nectar.

Credit:

L. Buss, UF/IFAS

[Click thumbnail to enlarge.]

Distribution

By the end of 2008, the larra wasp had spread into much of north and central Florida and had penetrated into parts of South Florida (Figure 16). It also expanded its range into southern and eastern Georgia and coastal areas of Alabama and Mississippi. More recently it has been reported from eastern South Carolina and southeastern North Carolina. In northern Florida, larra wasp adults are active from late April until the first hard frost; in southern Florida, activity may persist year-round, offering even greater mole cricket suppression.

Figure 16.

Distribution of larra wasp in Florida.

Credit:

J. H. Frank, UF/IFAS

[Click thumbnail to enlarge.]

Brazilian Red-Eyed Fly

This tachinid fly was introduced from South America to suppress invasive mole crickets. The Brazilian red-eyed fly is distributed in the southern and central parts of Florida with the northern boundary reaching Alachua County (Figure 17). The fly parasitizes a pest mole cricket adult by depositing a larva nearby, the larva finds the adult, develops inside it, and kills it. Golf courses inhabited by the Brazilian red-eyed fly have considerably less damage than those without the fly.

Figure 17.

Distribution of Brazilian red-eyed fly in Florida.

Credit:

T. Walker, UF

[Click thumbnail to enlarge.]

Figure 18.

Brazilian red-eyed fly pupa next to mole cricket .

Credit:

L. Buss, UF

[Click thumbnail to enlarge.]

Figure 19.

Brazilian red-eyed fly adult.

Credit:

L. Buss, UF

[Click thumbnail to enlarge.]

Mole Cricket Predators

Naturally occurring predators of mole crickets include raccoons, opossums, armadillos, birds, spiders, tiger beetles, and many other insectivorous animals. Unfortunately, foraging by some of these predators, especially armadillos, can cause considerable damage to turfgrass.

Chemical Control

Mole cricket IPM includes the use of insecticides when necessary; however, applications can be expensive and disruptive to biological control. Apply an insecticide only when the plant damage threshold is met or exceeded, and follow the instructions on the label. Time applications and target them to infested areas, thus reducing costs and environmental risks. On golf courses, for example, it’s frequently most effective to apply insecticides only to fairways, greens, and tees, leaving roughs and driving ranges untreated to maintain populations of beneficial organisms. Small nymphs feeding and growing during the summer months are more susceptible to insecticides than large nymphs present in late summer and fall.

The tables below list the insecticide active ingredients for products in the National Pesticide Information Retrieval System (http://npirspublic.ceris.purdue.edu/) that are currently registered for use in Florida on pest mole crickets in residential lawns, golf courses and athletic fields, pastures, and on vegetables. Registrations for Florida specified 2014 as the year of last registration. Listed are biologically active ingredients that kill pest mole crickets. To minimize resistance to insecticides, products should be rotated based on the Insecticide Resistance Action Committee (IRAC) group numbers. The tables and associated appendix in this publication serve as guides only: keep in mind that the information in them is likely to be outdated because both regulations and registrations are constantly changing.

The appendix includes registered insecticide products formulated with the active ingredients listed in the tables. Restricted-use insecticides must be applied by a licensed applicator. You must read and understand the current product label before applying any insecticide. The label lists all specific sites and pests for which an insecticide may be applied legally. It also displays a signal word indicating the relative toxicity of the product to mammals: slightly toxic (CAUTION), moderately toxic (WARNING), or highly toxic (DANGER).

Table 3.

Residential Lawns1

Active Ingredient

IRAC Number

Active Ingredient

IRAC Number

Azadirachtin

29

Esfenvalerate

3A

Beauveria bassiana

Biopesticide

Fipronil

2B

Beta-cyfluthrin

3A

Gamma-cyhalothrin

3A

Beta-cyfluthrin &

imidacloprid

3A

4A

Imidacloprid

4A

Bifenthrin

3A

Imidacloprid & lambda-cyhalothrin

4A

3A

Bifenthrin &

imidacloprid

3A

4A

Indoxacarb

22A

Bifenthrin &

zeta-cypermethrin

3A

3A

Lambda-cyhalothrin

3A

Bifenthrin

imidacloprid &

zeta-cypermethrin

3A

4A

3A

Permethrin

3A

Carbaryl

1A

Piperonyl butoxide, esfenvalerate & prallethrin

27A

3A

3A

Carbaryl &

bifenthrin

1A

3A

Thiamethoxam

4A

Clothianidin

4A

Thiamethoxam &

azoxystrobin (fungicide)

4A

Clothianidin &

bifenthrin

4A

3A

Thiamethoxam & lambda-cyhalothrin

4A

3A

Cyfluthrin

3A

Trichlorfon

1B

Cypermethrin

3A

Zeta-cypermethrin

3A

Deltamethrin

3A

1 Insecticide applications on residential lawns may require a period of time before use is permitted. Be sure to read the entire label before applying any insecticide.

Table 4.

Golf Courses and Athletic Fields1

Active Ingredient

IRAC Number

Active Ingredient

IRAC Number

Acephate

1B

Fipronil

2B

Allyl isothiocyanate & capsaicin

--

Imidacloprid

4A

Beauveria bassiana

Biopesticide

Indoxacarb

22A

Beta-cyfluthrin

3A

Lambda-cyhalothrin

3A

Bifenthrin

3A

Permethrin

3A

Bifenthrin &

imidacloprid

3A

4A

Piperonyl butoxide &

permthrin

27A

3A

Bifenthrin &

zeta-cypermethrin

3A

3A

Piperonyl butoxide &

pyrethrins

27A

3A

Bifenthrin

imidacloprid &

zeta-cypermethrin

3A

4A

3A

Pyrethrins

3A

Carbaryl &

bifenthrin

1A

3A

Thiamethoxam

4A

Chlorpyrifos

1B

Thiamethoxam &

azoxystrobin (fungicide)

4A

--

Cyfluthrin

3A

Trichlorfon

1B

1 Insecticide applications on golf courses and athletic fields may require a period of time before use is permitted. Be sure to read the entire label before applying any insecticide.

Table 5.

Pastures1

Active Ingredient

IRAC Number

Beauveria bassiana

Biopesticide

Carbaryl

1A

Piperonyl butoxide & pyrethrins

27A

3A

Pyrethrins

3A

1 Insecticide applications on pastures may require a period of time before grazing or cutting are permitted. Be sure to read the entire label before applying any insecticide.

Table 6.

Vegetables1

Active Ingredient

IRAC Number

Beauveria bassiana

Biopesticide

Bifenthrin

3A

Carbaryl

1A

Piperonyl butoxide & pyrethrins

27A

3A

1 Insecticide applications on vegetables may require a period of time before harvesting and consumption are permitted. Be sure to read the entire label before applying any insecticide.

Section 6: Establish IPM Program

Develop a long-term, site-specific IPM program by combining cultural, biological, and chemical control measures to suppress pest mole crickets to levels that assure plant damage thresholds are not exceeded and that minimize costs and risks to humans and the environment. The program is based on plant selection and growing practices and mole cricket biology and management options.

The following are guidelines to consider in developing an IPM program for turfgrass:

Use a tolerant grass cultivar or species, such as centipedegrass or zoysiagrass.

Acknowledgments

We thank Dennis Howard, Chief, Bureau of Pesticides and Bob Moore, Environmental Specialist in the Pesticide Registration Section, Bureau of Pesticides, Division of Agricultural Environmental Services, Florida Department of Agriculture and Consumer Services, for guidance and assistance with searching the National Pesticide Information Retrieval System. Fred Fishel, Director, UF/IFAS Pesticide Information Office, provided access to the system. He and John Capinera, Chair, UF/IFAS Entomology and Nematology Department, contributed helpful reviews of the manuscript. The work was supported by the USDA, NIFA, EIPM-CS program, and the Southern Region IPM Center.

Appendix

The National Pesticide Information Retrieval System (http://npirspublic.ceris.purdue.edu/) was used to compile the list of registered insecticide products in this appendix. This retrieval system is available by subscription. The first search criterion was “pest to be controlled,” so we used the keyword “mole cricket” and selected all four resulting variations—mole crickets, mole crickets (larvae), mole crickets (nymphs), and mole crickets (adults). Most of the products have not been tested for efficacy by the University of Florida. The application sites and respective site-specific keywords or categories were as follows:

Residential Lawns: For the specific keyword we used “lawn.” For sites, we selected all ornamental lawns and turf, including bahiagrass, bermudagrass, centipedegrass, ryegrass, and St. Augustinegrass.

Pastures: Within the list generated by the agriculture site category, “forage, fodder, hay and silage grasses,” we selected forage-fodder grasses, pastures, bermudagrass, bahiagrass, and rangeland.

Vegetables: Within the agriculture site category, we selected cucurbits, fruiting vegetables, leafy vegetables, root crop vegetables, seed and pod vegetables, and miscellaneous vegetables, and within those categories we included all crops that might be infested by mole crickets.

The insecticide lists given below serve as a guide only; keep in mind that the information given will likely become outdated because both regulations and registrations are constantly changing. The applicator holds full responsibility in verifying the legal usage and assumes all associated liability when applying any pesticide. Before applying an insecticide listed, verify your target pest and specific site of application are permitted by consulting the product’s label and always wear proper personal protective equipment.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other UF/IFAS Extension publications, contact your county's UF/IFAS Extension office.

U.S. Department of Agriculture, UF/IFAS Extension Service, University of Florida, IFAS, Florida A & M University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Nick T. Place, dean for UF/IFAS Extension.